Class DebugTreeAdaptor

java.lang.Object
org.antlr.runtime.debug.DebugTreeAdaptor
All Implemented Interfaces:
TreeAdaptor
public class DebugTreeAdaptor extends Object implements TreeAdaptor
A TreeAdaptor proxy that fires debugging events to a DebugEventListener delegate and uses the TreeAdaptor delegate to do the actual work. All AST events are triggered by this adaptor; no code gen changes are needed in generated rules. Debugging events are triggered *after* invoking tree adaptor routines. Trees created with actions in rewrite actions like "-> ^(ADD {foo} {bar})" cannot be tracked as they might not use the adaptor to create foo, bar. The debug listener has to deal with tree node IDs for which it did not see a createNode event. A single <unknown> node is sufficient even if it represents a whole tree.

  • Field Details

  • Constructor Details

  • Method Details

    • create

      public Object create(Token payload)
      Description copied from interface: TreeAdaptor
      Create a tree node from Token object; for CommonTree type trees, then the token just becomes the payload. This is the most common create call. Override if you want another kind of node to be built.
      Specified by:
      create in interface TreeAdaptor

    • errorNode

      public Object errorNode(TokenStream input, Token start, Token stop, RecognitionException e)
      Description copied from interface: TreeAdaptor
      Return a tree node representing an error. This node records the tokens consumed during error recovery. The start token indicates the input symbol at which the error was detected. The stop token indicates the last symbol consumed during recovery. You must specify the input stream so that the erroneous text can be packaged up in the error node. The exception could be useful to some applications; default implementation stores ptr to it in the CommonErrorNode. This only makes sense during token parsing, not tree parsing. Tree parsing should happen only when parsing and tree construction succeed.
      Specified by:
      errorNode in interface TreeAdaptor

    • dupTree

      public Object dupTree(Object tree)
      Description copied from interface: TreeAdaptor
      Duplicate tree recursively, using dupNode() for each node
      Specified by:
      dupTree in interface TreeAdaptor

    • simulateTreeConstruction

      protected void simulateTreeConstruction(Object t)
      ^(A B C): emit create A, create B, add child, ...

    • dupNode

      public Object dupNode(Object treeNode)
      Description copied from interface: TreeAdaptor
      Duplicate a single tree node. Override if you want another kind of node to be built.
      Specified by:
      dupNode in interface TreeAdaptor

    • nil

      public Object nil()
      Description copied from interface: TreeAdaptor
      Return a nil node (an empty but non-null node) that can hold a list of element as the children. If you want a flat tree (a list) use "t=adaptor.nil(); t.addChild(x); t.addChild(y);"
      Specified by:
      nil in interface TreeAdaptor

    • isNil

      public boolean isNil(Object tree)
      Description copied from interface: TreeAdaptor
      Is tree considered a nil node used to make lists of child nodes?
      Specified by:
      isNil in interface TreeAdaptor

    • addChild

      public void addChild(Object t, Object child)
      Description copied from interface: TreeAdaptor
      Add a child to the tree t. If child is a flat tree (a list), make all in list children of t. Warning: if t has no children, but child does and child isNil then you can decide it is ok to move children to t via t.children = child.children; i.e., without copying the array. Just make sure that this is consistent with have the user will build ASTs. Do nothing if t or child is null.
      Specified by:
      addChild in interface TreeAdaptor

    • becomeRoot

      public Object becomeRoot(Object newRoot, Object oldRoot)
      Description copied from interface: TreeAdaptor
      If oldRoot is a nil root, just copy or move the children to newRoot. If not a nil root, make oldRoot a child of newRoot. old=^(nil a b c), new=r yields ^(r a b c) old=^(a b c), new=r yields ^(r ^(a b c)) If newRoot is a nil-rooted single child tree, use the single child as the new root node. old=^(nil a b c), new=^(nil r) yields ^(r a b c) old=^(a b c), new=^(nil r) yields ^(r ^(a b c)) If oldRoot was null, it's ok, just return newRoot (even if isNil). old=null, new=r yields r old=null, new=^(nil r) yields ^(nil r) Return newRoot. Throw an exception if newRoot is not a simple node or nil root with a single child node--it must be a root node. If newRoot is ^(nil x) return x as newRoot. Be advised that it's ok for newRoot to point at oldRoot's children; i.e., you don't have to copy the list. We are constructing these nodes so we should have this control for efficiency.
      Specified by:
      becomeRoot in interface TreeAdaptor

    • rulePostProcessing

      public Object rulePostProcessing(Object root)
      Description copied from interface: TreeAdaptor
      Given the root of the subtree created for this rule, post process it to do any simplifications or whatever you want. A required behavior is to convert ^(nil singleSubtree) to singleSubtree as the setting of start/stop indexes relies on a single non-nil root for non-flat trees. Flat trees such as for lists like "idlist : ID+ ;" are left alone unless there is only one ID. For a list, the start/stop indexes are set in the nil node. This method is executed after all rule tree construction and right before setTokenBoundaries().
      Specified by:
      rulePostProcessing in interface TreeAdaptor

    • addChild

      public void addChild(Object t, Token child)

    • becomeRoot

      public Object becomeRoot(Token newRoot, Object oldRoot)
      Description copied from interface: TreeAdaptor
      Create a node for newRoot make it the root of oldRoot. If oldRoot is a nil root, just copy or move the children to newRoot. If not a nil root, make oldRoot a child of newRoot. Return node created for newRoot. Be advised: when debugging ASTs, the DebugTreeAdaptor manually calls create(Token child) and then plain becomeRoot(node, node) because it needs to trap calls to create, but it can't since it delegates to not inherits from the TreeAdaptor.
      Specified by:
      becomeRoot in interface TreeAdaptor

    • create

      public Object create(int tokenType, Token fromToken)
      Description copied from interface: TreeAdaptor
      Create a new node derived from a token, with a new token type. This is invoked from an imaginary node ref on right side of a rewrite rule as IMAG[$tokenLabel]. This should invoke createToken(Token).
      Specified by:
      create in interface TreeAdaptor

    • create

      public Object create(int tokenType, Token fromToken, String text)
      Description copied from interface: TreeAdaptor
      Same as create(tokenType,fromToken) except set the text too. This is invoked from an imaginary node ref on right side of a rewrite rule as IMAG[$tokenLabel, "IMAG"]. This should invoke createToken(Token).
      Specified by:
      create in interface TreeAdaptor

    • create

      public Object create(int tokenType, String text)
      Description copied from interface: TreeAdaptor
      Create a new node derived from a token, with a new token type. This is invoked from an imaginary node ref on right side of a rewrite rule as IMAG["IMAG"]. This should invoke createToken(int,String).
      Specified by:
      create in interface TreeAdaptor

    • getType

      public int getType(Object t)
      Description copied from interface: TreeAdaptor
      For tree parsing, I need to know the token type of a node
      Specified by:
      getType in interface TreeAdaptor

    • setType

      public void setType(Object t, int type)
      Description copied from interface: TreeAdaptor
      Node constructors can set the type of a node
      Specified by:
      setType in interface TreeAdaptor

    • getText

      public String getText(Object t)
      Specified by:
      getText in interface TreeAdaptor

    • setText

      public void setText(Object t, String text)
      Description copied from interface: TreeAdaptor
      Node constructors can set the text of a node
      Specified by:
      setText in interface TreeAdaptor

    • getToken

      public Token getToken(Object t)
      Description copied from interface: TreeAdaptor
      Return the token object from which this node was created. Currently used only for printing an error message. The error display routine in BaseRecognizer needs to display where the input the error occurred. If your tree of limitation does not store information that can lead you to the token, you can create a token filled with the appropriate information and pass that back. See BaseRecognizer.getErrorMessage().
      Specified by:
      getToken in interface TreeAdaptor

    • setTokenBoundaries

      public void setTokenBoundaries(Object t, Token startToken, Token stopToken)
      Description copied from interface: TreeAdaptor
      Where are the bounds in the input token stream for this node and all children? Each rule that creates AST nodes will call this method right before returning. Flat trees (i.e., lists) will still usually have a nil root node just to hold the children list. That node would contain the start/stop indexes then.
      Specified by:
      setTokenBoundaries in interface TreeAdaptor

    • getTokenStartIndex

      public int getTokenStartIndex(Object t)
      Description copied from interface: TreeAdaptor
      Get the token start index for this subtree; return -1 if no such index
      Specified by:
      getTokenStartIndex in interface TreeAdaptor

    • getTokenStopIndex

      public int getTokenStopIndex(Object t)
      Description copied from interface: TreeAdaptor
      Get the token stop index for this subtree; return -1 if no such index
      Specified by:
      getTokenStopIndex in interface TreeAdaptor

    • getChild

      public Object getChild(Object t, int i)
      Description copied from interface: TreeAdaptor
      Get a child 0..n-1 node
      Specified by:
      getChild in interface TreeAdaptor

    • setChild

      public void setChild(Object t, int i, Object child)
      Description copied from interface: TreeAdaptor
      Set ith child (0..n-1) to t; t must be non-null and non-nil node
      Specified by:
      setChild in interface TreeAdaptor

    • deleteChild

      public Object deleteChild(Object t, int i)
      Description copied from interface: TreeAdaptor
      Remove ith child and shift children down from right.
      Specified by:
      deleteChild in interface TreeAdaptor

    • getChildCount

      public int getChildCount(Object t)
      Description copied from interface: TreeAdaptor
      How many children? If 0, then this is a leaf node
      Specified by:
      getChildCount in interface TreeAdaptor

    • getUniqueID

      public int getUniqueID(Object node)
      Description copied from interface: TreeAdaptor
      For identifying trees. How to identify nodes so we can say "add node to a prior node"? Even becomeRoot is an issue. Use System.identityHashCode(node) usually.
      Specified by:
      getUniqueID in interface TreeAdaptor

    • getParent

      public Object getParent(Object t)
      Description copied from interface: TreeAdaptor
      Who is the parent node of this node; if null, implies node is root. If your node type doesn't handle this, it's ok but the tree rewrites in tree parsers need this functionality.
      Specified by:
      getParent in interface TreeAdaptor

    • getChildIndex

      public int getChildIndex(Object t)
      Description copied from interface: TreeAdaptor
      What index is this node in the child list? Range: 0..n-1 If your node type doesn't handle this, it's ok but the tree rewrites in tree parsers need this functionality.
      Specified by:
      getChildIndex in interface TreeAdaptor

    • setParent

      public void setParent(Object t, Object parent)
      Specified by:
      setParent in interface TreeAdaptor

    • setChildIndex

      public void setChildIndex(Object t, int index)
      Specified by:
      setChildIndex in interface TreeAdaptor

    • replaceChildren

      public void replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t)
      Description copied from interface: TreeAdaptor
      Replace from start to stop child index of parent with t, which might be a list. Number of children may be different after this call. If parent is null, don't do anything; must be at root of overall tree. Can't replace whatever points to the parent externally. Do nothing.
      Specified by:
      replaceChildren in interface TreeAdaptor

    • getDebugListener

      public DebugEventListener getDebugListener()

    • setDebugListener

      public void setDebugListener(DebugEventListener dbg)

    • getTreeAdaptor

      public TreeAdaptor getTreeAdaptor()